With a device for controlling the engine output of a machine, such as for example a construction machine, a technique is known (for example, refer to Patent Document #1) of calculating the total load of various types of load machinery such as a hydraulic motor, an air conditioner, a hydraulic pump, and so on, which changes from one moment to the next, and of setting the gross output of the engine by adding this total load to the main output needed for working.
According to this type of control device, it is possible to ensure the main output needed for working, even if the load of operating auxiliary machinery such as a fan and an air conditioner and so on fluctuates.